Process for weighing poultry, and conveyor hook for carrying out this process

ABSTRACT

A method of weighing poultry includes: conveying a plurality of birds which are closely adjacent to each other toward a weighing station; disentangling the wings of the birds from each other and separating the birds from each other by turning the birds; and then, while the wings of the birds are disentangled and while the birds are separated from each other, weighing the birds at the weighing station. The birds are suspended by their legs from suspension hooks and the suspension hooks are suspended from a conveyor suspension track.

This is a division of application Ser. No. 341,721, filed Apr. 21, 1989,now U.S. Pat. No. 4,972,549.

BACKGROUND OF THE INVENTION

The invention relates to a process for weighing poultry which isconveyed suspended by the legs from suspension hooks directed in thedirection of conveyance through a conveyor suspension track past aweighing station, characterized in that prior to reaching the weighingposition each of the hooks is turned through such an angle that duringthe weighing no contact between the birds, which would adversely affectweighing, occurs. The invention also relates to a conveyor hook forcarrying out this process.

DESCRIPTION OF THE PRIOR ART

Poultry which is conveyed suspended in the suspension hook of a conveyorbelt past different processing stations has to be weighed at variousstages of the processing, i.e. between various processing stations. Thisis not only because the weight of the product in the poultry slaughterbusiness is an important factor for the correct setting of the variousprocessing machines, but also because the weight is an important meansof checking the various operations carried out, both as regards theeffective removal of parts not fit for consumption and as regardsmonitoring of the efficiency in operations such as cooling, jointing,boning, etc.

Weighing of poultry advanced on such a conveyor belt does, however, inpractice give rise to problems. In order to achieve the greatestpossible capacity of conveyor belt and slaughter and processing plant,the birds on the conveyor belt have the smallest possible distancebetween them, with the result that the birds are constantly touchingeach other, in particular by the wings. Regardless of the weighingmethod used, this means that the weight determined is often not correct,because this contact between the birds interferes with the weighingresult.

This is seen particularly when the weighing is carried out in the mannerknown from NL-A-6511938, in which the hooks with the birds suspendedfrom them are raised one by one in the weighing station, so that theyare relieved of the pulling forces and resistances exerted by theconveyor belt.

An obvious solution to eliminate this problem is to increase thedistance between the individual birds, but this, of course,proportionately reduces the capacity of the slaughter and processingplant. If an attempt is made to compensate this decrease in capacity byincreasing the speed of the conveyor belt, other serious problems areencountered.

The object of the invention is to produce a process which is simple tocarry out and a conveyor hook for carrying out this process, which canbe used simply and cheaply in existing plants while retaining the smalldistance between birds, and with which it is possible for the birds tohang entirely free of each other during weighing, without changing theconveyor belt.

This object is achieved according to the invention in that prior toreaching the weighing position each of the hooks is turned through suchan angle that during the weighing no contact between the birds, whichwould adversely affect the weighing result, occurs.

With this simple measure, which can easily be achieved in existingplants, weighing can be carried out accurately without any problems atall. This means that it is also more attractive to fit weighing stationsat several points along the conveyor belt, with all the advantagesthereof.

If the poultry carcasses are suspended in a regular and correct mannerfrom the conveyor belt, the turning of the hooks, with the separationfrom each other of the wings thereby envisaged, will not give rise toproblems, but in practice it is sometimes found that the carcasses arealready suspended from the hooks in such an irregular way that the wingsof adjacent birds are already caught in each other, so that when thehooks are subsequently turned problems still arise.

Various methods by which entangled wings of adjacent birds can bereleased from each other are possible. Prior to weighing the hooks can,while turning them, be displaced relative to each other in the verticaldirection. The birds can be conveyed along a track stretch an angle withthe horizontal, while it is also possible that, prior to or followingthe turning of the hooks, the birds are displaced relative to each otherin a direction at right angles to the direction of conveyance. It mustbe pointed out here that this releasing operation has to be carried outonly once, following which the birds can be turned out of the plane ofthe belt any desired number of times.

A conveyor hook for carrying out the process according to the inventioncomprises a suspension part for accommodating the legs of a bird, acoupling part to be coupled to the conveyor suspension track andsupporting element(s) cooperating with at least one supporting platformof a weighing device for taking the weight of the suspension part andthe bird hanging from it during the weighing, the suspension part beingconnected to a supporting rod which is guided in an aperture formed inthe center of a shaft and at right angles to the axis thereof, saidshaft carrying at each of its ends a supporting roller, and beingrotatably accommodated in the, forked, carrier which has a guide trackwhich is parallel to the shaft and has an end part crossing the shaft atan acute angle, cooperating with a boss projecting at right angles fromthe carrier rod, in such a way that turning of the carrier around theshaft brings about a controlled angular displacement of the carrier rodaround the axis thereof.

Preferably the guide track is formed in a plate interconnecting the legsof the forked carrier.

Preferably the conveyor suspension track includes an angle with thehorizontal on a track part preceding a weighing station and is designedso that it is ascending along that stretch.

Preferably there are means for turning the hooks while the track part isbeing covered, preferably a controlled ram which can be moved at rightangles to the direction of conveyance and acts on the successive birds,or a first and a second guide wheel which are displaced relative to eachother in the direction of conveyance and which can each be driven sothat they rotate in the direction of conveyance, and which each extendwith the outer periphery to below the path for the poultry.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a part of a conveyor suspension track forpoultry, in which a weighing station is incorporated and the measuresaccording to the invention are used;

FIG. 2 is a schematic representation of a part of a conveyor suspensiontrack with suspension hooks and poultry suspended therefrom which arefreed from each other prior to turning;

FIG. 3 is a top view of a second embodiment according to the inventionfor freeing the birds from each other;

FIG. 4 is a top view of a third embodiment for freeing the birds fromeach other;

FIG. 5 is a side view of a part of a conveyor hook preferably usedaccording to the invention;

FIG. 6 is an end view thereof;

FIG. 7 is a top view thereof; and

FIG. 8 is a view in the direction of the arrows VIII-VIII in FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1 reference numeral 2 shows a conveyor suspension track, knownper se, on which poultry is moved along suspended from conveyor hooks, anumber of which are shown and indicated by 4a-4i. Each hook hangs from abearing rod 6 having at the end a bearing roller 8 resting on a guide10; the rollers are connected to each other by means of the cable 12,and the direction of movement of the whole unit is indicated by thearrow 14.

Along the conveyor track 2 is a weighing station 16, known per se, andcomprising a platform 18 which is carried by a device 20, known per se,for determining the weight acting upon the platform; the connectionthereto is symbolized by the dotted lines 22a, 22b. As is known, whenthe weighing station 16 is reached the weight of the hook and the birdsuspended from it is no longer borne by the conveyor track 2, but by theplatform 18, which in fact is made up of two parts 18a, 18b coupledtogether (see FIG. 6). For this, each hook is provided with twosupporting elements, such as supporting rollers 24a, 24b (see FIGS. 5 to7) and the platform 18 lies above the normal level of the supportingrollers indicated by the dotted line 26 in FIG. 1; a run-on part 28 isprovided before the platform 18, to take the hook to the higher level.Following the platform 18 there is a corresponding run-off part 30. Whenthey reach the weighing station 16 the hooks are thus raised, and eachhook then rests only with the supporting rollers 24a, 24b first on therun-on part 28, then on the weighing platform, and subsequently on therun-off part 30, and during weighing the hook with the bird suspendedtherefrom is free from interfering influences (shocks, impacts) whichcould be exerted by the conveyor track 2. This technique is known perse, for example from NL-A-6511938.

It is clear that, for the sake of the greatest possible capacity of theconveyor track, the distance between the suspension hooks will be keptas short as possible, which is no problem for the operations to becarried out normally on the birds. It does mean, however, that the birdsare constantly in contact with each other, with the result that duringweighing wrong results are obtained through their interaction.

The invention is based on the idea that this interaction can beeliminated by ensuring that during weighing the hooks are turned througha specific angle, for example 45 degrees, relative to each other, withthe result that the wings of adjacent birds, projecting sideways fromthe body, are completely released from each other, and interferingeffects are thus ruled out.

The figure shows how the hooks 4a to 4c with the birds 32a to 32csuspended therefrom still remain in the normal position in which thewings of adjacent birds are in contact with each other. The hooks 4e to4g are, however, turned through 45 degrees relative to the vertical, ofcourse with the birds 32e to 43g suspended therefrom, the result beingthat the wings of these birds will no longer touch each other, so thatduring the weighing of a bird--in FIG. 1 this is thus the bird 32f--itis completely free from the interfering influence of adjacent birds. Thehook 4i with the bird 32g suspended therefore is again in the normalposition. The hooks 4d and 4h are in a transitional position. Anessential feature of the invention is thus that during the weighing thehook from which the bird to be weighed is suspended is turned through aspecific angle relative to the normal direction; as the figure shows,the two adjacent hooks may also be turned through a specific angle(which need not be equal to the maximum turning angle). This turningcan, of course, be achieved in various ways, and a preferred embodimentof a simple structure with which this turning is achieved will now bedescribed below, but another problem connected with the process anddevice proposed according to the invention will be discussed first. Theinvention offers various methods of eliminating this problem.

FIG. 2 shows schematically a conveyor suspension track 40 with itssuspension hooks 42 and the birds 44 hanging thereon. As the figureshows, this conveyor track comprises a part 40a at a certain level, arising part 40b, and then a horizontal part 40c. In the rising part 40bthe birds are moved over a certain distance `a` in the verticaldirection relative to each other, the wings, of course, also undergoingsuch a displacement; if the wings of birds brought in by the part 40aare entangled, these wings will be released from each other in the trackpart 40b. There are preferably provisions--not shown in the figure--forturning the hooks through a particular angle; their design will, ofcourse, depend on the design of the hooks.

FIG. 3 shows a schematically indicated conveyor suspension track 50 fromwhich each of the birds is moved to a particular position, indicated by52, in the direction at right angles to the direction of conveyanceindicated by the arrow 54. This is carried out by a ram 56 driven by apneumatic cylinder 58 which works in combination with a control device60 which is not described in greater detail. This control device 60 iscontrolled by a position detector comprising, for example, a lightsource 62 and a photo-electric cell 64, which detects the presence of abird, such as the bird 66, and in response thereto produces an actuationsignal for the pneumatic cylinder 58 at a moment at which the detectedbird 66 has reached the position 52. The schematically shown stop 68ensures correct prepositioning of the bird, and the ram 56 then pushesthis bird out of the plane of the track 50. In this way the wings of thebird come free from those of the adjacent bird. A second guide 70handles the repositioning of the bird.

FIG. 4 shows schematically another solution. The poultry 82 hanging fromthe conveyor track indicated schematically by the line 80 is herealready turned through a specific angle relative to the plane of thetrack and is being conveyed in the direction of the arrows 84. A firstguide wheel 88 rotating in the direction of the arrow 86, whose outerperiphery extends close up to the vertical plane of the track 80,presses the birds, such as the bird 82a, in the direction of the arrow90 out of the plane of the track and when this bird subsequently reachesthe position indicated by 82b a second rotary guide wheel 94 driven inthe direction of the arrow 92 presses the bird again in the direction ofthe arrow 96 back towards the plane of the track 80. In this wayentangled wings are released from each other with simple means, but inan effective manner.

Finally, a fourth solution must be mentioned, which involves subjectingthe hooks to turning through a large angle, for example 60° : here thewings come entirely free from each other, and after the subsequentturning back are completely free from each other.

Of course, the turning of the suspension part of the suspension hooksrelative to the normal direction can be achieved in various ways. FIGS.5 to 8 show an embodiment of a suspension hook which is particularlysuitable for use in a weighing device of the type shown in FIG. 1, i.e.a hook which is raised while running into the weighing station andduring its movement through the weighing station rests on supportingrollers. These supporting rollers 24a and 24b are mounted--see FIGS.5-8--on the ends of a shaft 11 which is designed with a bore 13 which isat right angles to the axis, and through which the supporting rod 15goes, said supporting rod being firmly connected by one end to thesuspension part 17 and at the other, threaded end bears a locking nut19. This supporting rod 15 also has a boss 21 projecting at rightangles, the function of which will be explained in greater detail below.Around the shaft 11 is a forked supporting piece 23, with the projectingcarrier 25 which is connected to the bar 6 of the conveyor track 2 (seeFIG. 1). This forked supporting piece 23 is closed at one side by aclosing plate 27 in which a guide track 29 is formed. When the part 25takes up the position indicated by solid lines in FIG. 5 the boss 21 isin the lowest part 29a of the guide track 29 which crosses the shaft 11at right angles, and the hook is in the position indicated in FIGS. 1and 5, in which the plane of the hook coincides with a vertical planethrough the conveyor track. If, however, the part 25 is turned through90 degrees to the position 25a shown by dotted lines in FIG. 5--which isthe case (see FIG. 1) when the supporting rollers 24a, 24b are raised inthe run-up part 28--the boss 21 comes to rest in the top part of theguide track 29 running off at an angle to the right and crossing theshaft 11 at an angle of 45° (the position according to FIG. 6), and thesupporting rod 15 with the suspension part 17 is hereby turned out ofthis plane through an angle which is determined by the shape of theguide track and can be, for example, 45° (a value which is, of course,only given by way of example). This achieves the envisaged effect:turning of the hook into the weighing position.

What is claimed is:
 1. A system for weighing poultry, comprising:aconveyor system for conveying a plurality of birds toward a weighingstation, the conveyor system including suspension hooks for suspendingthe birds by their legs, the conveyor system further including aconveyor suspension track, the suspension hooks being suspended from theconveyor suspension track; disentangling and separating means fordisentangling the wings of the birds and separating the birds from eachother, the disentangling and separating means including means forturning the birds; and means for weighing the birds and the weighingstation while the wings of the birds are disentangled and while thebirds are separated from each other.
 2. The system of claim 1, whereinthe disentangling and separating means further includes displacing meansfor individually displacing the birds in a horizontal direction at rightangles to the conveyor suspension track.
 3. The system of claim 2,wherein the displacing means includes a controlled ram.
 4. The system ofclaim 2, wherein the displacing means includes a pair of oppositelyrotatable guide wheels.
 5. The system of claim 2, wherein the conveyorsuspension track includes an angled portion for displacing the birdswith respect to each other in the vertical direction prior to weighingthe birds, the angled portion of the conveyor suspension track beingassociated with the turning means such that the birds are turned by theturning means as the birds are displaced in the vertical direction bythe angled portion of the conveyor suspension track.
 6. A conveyor hook,comprising:a suspension part for suspending a bird; a coupling part forcoupling the suspension part to a conveyor suspension track; and supportmeans for (a) supporting the suspension part and the bird on a weighingmeans and (b) raising the suspension part and the bird onto the weighingmeans; wherein the coupling part is hinged to the suspension part suchthat the coupling part rotates with respect to the suspension part asthe suspension part is raised onto the weighing means; and wherein thesuspension part includes a boss and the coupling part includes a guidetrack for cooperating with the boss to turn the suspension part and thebird as the coupling part rotates with respect to the suspension part.7. The conveyor hook of claim 6, wherein the support means includes ashaft with two ends, the support means further including supportingrollers, the rollers being located at the ends of the shafts.
 8. Theconveyor hook of claim 7, wherein the suspension part includes asupporting rod, the shaft including a central aperture, the supportingrod being located within the central aperture, the boss extending atright angles from the supporting rod.
 9. The conveyor hook of claim 8,wherein the coupling part includes a fork, the shaft being rotatablyaccommodated in the fork, the guide track being located within the fork.10. The conveyor hook of claim 9, wherein the guide track is generallyparallel to the shaft and includes an end part which crosses the shaftat an acute angle.
 11. The conveyor hook of claim 10, wherein the forkincludes two legs and a plate which interconnects the legs, the guidetrack being formed within the plate.